[irixusr]

You can use a bank of capacitors and the power itself is not a huge deal (still not trivial, but it's been done for 60+ years).

The problem is also that at 1kW for every 1Mw you still only use 0.1% of the energy you pumped in. And the energy requirements are still large because you are firing this thing repeatedly. Assuming the same amount of energy is required to ablate the atoms as with conventional UV (I'm not in the field, but its probably not a bad assumption), you have to multiply the ratio of the efficiencies of both methods to get at the energy required. Could be several multiples more if not an order of magnitude.

Also where does the remaining 999kW go? Eventually heat, so you have to spend 2Mw more to cool it (assuming 50% AC efficiency, I guess you could pump cold water instead). Add in the energy costs of opening and closing a vacuum lock and this is a fun project to be working on :D